/*
 * Copyright (C) 2008 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.gxp.compiler.parser;

import com.google.gxp.compiler.alerts.AlertSink;
import com.google.gxp.compiler.alerts.SourcePosition;

import java.io.IOException;
import java.io.InputStream;

/**
 * Resolves entities in source files.
 *
 * <p>
 * The interface is similar to
 * {@link org.xml.sax.EntityResolver SAX entity resolver} but an entity includes
 * the position of the entity in the source.
 */
public interface SourceEntityResolver {

  /**
   * @param entityPos position of the entity reference.
   * @param publicId possibly null
   * @param systemId possibly null
   * @param alertSink receives info and warnings messages
   */
  InputStream resolveEntity(
      SourcePosition entityPos, String publicId, String systemId,
      AlertSink alertSink)
      throws IOException;

}
